Basically, the final ending "-어요" is a standard word, and "-에요" is a dialect of 서울(Seoul) of "-어요". For examples,

가다. (to go)가-시-다 (honorific form of 가다, used with the honorific ending/inffix '-시-' )가-시-어요, 가시어요, (the final ending '-어요' is added)가셔요. (This form is contraction of '가시어요', and this is a standard word)

However, the people in Seoul tend to speak it '가세요', not '가셔요'. This form is also granted as a standard word since when the government of Korea admitted it as a standard word in the middle of 1980s.